1. HUD

Add block for the joined message, like 'Player joined Team' (red, blue, spectators, game). It makes sense because Fragged message already exists, so one can tweak FragMessage perfectly, then all of the sudden Joined message will pop in it's default format. Joined message can't even be removed without removing Fragged message since cg_centertime value overrides Time variable inside FragMessage block.

So in short i would suggest JoinedMessage block for the HUD.

2. Ban Logs

Currently bans are added in the format:

// Time - Date, Country, Country Code
Name { "Player" { Reason: "Reason" } }
IP { "IP address" { Reason: "Reason" } }
Guid { "Player's GUID" { Reason: "Reason" } }

I would suggest to add data with who triggered the ban inside the bans.txt, in the format you find the most convenient. For example to add in the 2nd line something like:

// Banned by AdminNick, AdminCC, AdminIP

This would make server management easier and more transparent.

3. Enemy Model

Separate model from the sound, by adding additional enemy sound variable. I've seen this in one older mod (spiterbot) and it can be quite interesting and helpful. In practice it would be like, for example:

xp_enemyColors "2222"
xp_enemyModel "tankjr/xp"
xp_enemySound "sarge"

In case of xp_enemySound "", sounds should be inhereted from the model as it is now.

Hope at least some of these ideas can be useful for the future. Cheers!